S_N2 Reactions of the Type,Nu^- + RL $\rightarrow$ Nu-R + L^-, are Favored:
A) When Tertiary Substrates Are

S_N2 reactions of the type,Nu^- + RL $\rightarrow$ Nu-R + L^-, are favored:

A) when tertiary substrates are used.
B) by using a high concentration of the nucleophile.
C) by using a solvent of high polarity.
D) by the use of weak nucleophiles.
E) by none of the above.